Its always difficult to be a pure archer because you always have to worry about arrow supply cuz ur using them all the time, unless you have the archery perk where you pick up more arrows that you shoot, but even that doesnt quite allow you to keep a bunch of arrows. It's always a pain to go to the fletcher in Solitude and he doesn't always have a lot of arrows, could fletching could be a cool skill? you could make bows and arrows and improve both bows and arrows, maybe add fire to arrows like the crossbow bolts?

I never have a problem running out of arrows. I did, once or twice when I first started, then I figured out who to kill to take their's. Ancient Nords' are as good as Steel, and all over creation, so I use those most. Steels can be taken off of Imperials, so clean out Fort Greymor, right in front of Whiterun, and wait a couple days. It will fill up with Imperials, and every time you clean it out, that's like 200 arrows. They respawn every couple days. If I'm running low, I have a backup supply of Irons, or Foresworn when those run out. That tells me it's time to go stock up again. I end up selling the Steel ones eventually, because they're just like Septims when I'm a little short on cash. I never actually BUY arrows any more, despite having several Hunter/Archer/Ranger characters. My Hunter doesn't even go into town. Hunter's Discipline is just a gateway perk to Ranger.

I have tons of arrows on my archer now. Whenever I pass through any town, I buy arrows by the bucket load. I have built up a stock of about 400 dwarven, elven and orcish, but for now i just use steel, ancient nord and anything lower (iron, forsworn and falmer arrows). I can get away with using the lower grade ones while I'm building up my massive supply of quality arrows.

Running through a few Nordic tomb type dungeons should also net you a good supply of Ancient Nordic Arrows. And if you're a Dawnguard vampire, there's a guy who always has a stock of 200 elven arrows in the castle (on top of that, you can get them made into sunburst or blood-cursed arrows for free).

Pre-Dawnguard, I had obtained ebony arrows to the thousands through purchasing, looting, etc. I didn't do the R-P exploit to have an archer shoot them. Mostly because I think the quiver looks cool, and that daedric and dragon arrows have a curved shaft.